1. Technical Field
The present invention relates to a ball, and in particular a soccer ball, which comprises a top layer complex and middle and backing layer complexes. Furthermore, the present invention relates to a method of producing a top layer complex of a ball.
2. Prior Art
Various methods of producing balls are known from the prior art. In addition to the balls of a very simple construction (single-layer plastic balls), hand-sewn balls, in particular, are used in areas requiring high quality.
A known method of producing hand-sewn soccer balls, footballs, rugby balls, handballs, etc. is described, for example, in the document WO 95/09034. The construction of such a previously known ball and its production method are described below with reference to FIG. 5.
A ball 10 of the hand-sewn type is illustrated in FIG. 5. As can be seen from the figure, the ball 10 has an inflatable bladder core 9 that may consist, for example, of vulcanized latex. Located in the bladder core 9 is a valve (not illustrated) by means of which the ball can be inflated. Located on the bladder core 9 in the example illustrated are three layer complexes: a structure 12 which may consist, for example, of two or more (three in the example illustrated) fabric layers is used as backing layer complex (also known as backing complex). The different fabric layers are bonded to one another by means of suitable binding agents (usually dispersions in an aqueous solution). A layer of polyethylene foam (PE) is used as middle layer complex 13. Finally, in the example illustrated, the top layer complex 14 consists of a transparent film. In this previously known ball, the decorative markings 15 on the ball (decorations, references to the manufacturer and registered trade marks, etc.) are located between the transparent layer 14 and the layer of polyethylene foam 13.
A previously known ball 10 of this type is produced by having the decorative markings 15 applied to the inner side of a finished transparent outer layer 14. Subsequently, the middle layer complex 13 and the backing layer complex 12 are laminated onto the printed side of the transparent covering layer 14. Subsequently, the laminate (produced over a large area) is die cut in order to produce flat shapes (the usual triangles, pentagons, hexagons) which, when joined together, result in a hollow sphere. The ball elements are then sewn together by hand. The ball skin, produced in this way, is then placed on the inflatable core 11 (in the case of a laminated ball), or the inflatable core (11) is inserted into the ball skin before it is closed, as in the case of a hand-sewn ball.
In a ball of the non-hand-sewn type, an inflatable core is wrapped with a multidirectional filament structure that is stabilized and held together by means of vulcanizable bonding. The top layer complex 14 produced according to the above method can be bonded into correspondingly provided recesses in the filament structure with the aid of a nonwoven material (a felt or mat).
However, previously known balls of this type and the production methods described have the following disadvantages: on the one hand, the trajectory properties of balls of this type are not optimum owing to the structure of the outer skin. The same applies to the bounce properties and the impact characteristics of the ball. Furthermore, a disadvantage of the production method described above consists in the fact that, because the foam layer 13 is laminated onto the printed, prefabricated film 14, the bonding of these layers to one another is not optimum, which has an adverse effect on the abrasion resistance of the markings 15. Furthermore, although the PU films used for the transparent film are light stabilized, they are not lightfast. As a result, undesirable "yellowing" of the ball may occur as a result of the adhesive bonding. Finally, the transparent PU films have the disadvantage that they are slippery in wet conditions, and make the ball difficult to control.
One object of the present invention is therefore to provide a high quality ball and a reliable method of producing it. A ball according to the invention has optimum bounce and trajectory properties, feels "soft" on the foot, is fast in flight, permits optimum handling and optimum ball control, and meets or exceeds the specifications required by FIFA. Furthermore, a ball according to the invention embodies a high degree of roundness and dimensional stability, a high degree of abrasion resistance, and a low degree of water absorption.